30 December 2009

http://www.foxnews.com/scitech/air-space/ci.Russia+May+Send+Spacecraft+to+Asteroid.opinionPrint- AP - December 30, 2009Russia's space chief said Wednesday his agency will consider sending a spacecraft to a large asteroid to knock it off its path and prevent a possible collision with Earth.MOSCOW— Russia is considering sending a spacecraft to a large asteroid to knock it off its path and prevent a possible collision with Earth, the head of the country's space agency said Wednesday.Anatoly Perminov said the space agency will hold a meeting soon to assess a mission to Apophis, telling Golos Rossii radio that it would invite NASA, the European Space Agency, the Chinese space agency and others to join the project once it is finalized.When the 885-foot asteroid was first discovered in 2004, astronomers estimated the chances of it smashing into Earth in its first flyby in 2029 were as high as 1-in-37, but have since lowered their estimate.SLIDESHOW: How Could Scientists Prevent an Asteroid Impact?Further studies ruled out the possibility of an impact in 2029, when the asteroid is expected to come no closer than 18,300 miles above Earth's surface, but they indicated a small possibility of a hit on subsequent encounters.In October, NASA lowered the odds that Apophis could hit Earth in 2036 from a 1-in-45,000 as earlier thought to a 1-in-250,000 chance after researchers recalculated the asteroid's path. It said another close encounter in 2068 will involve a 1-in-330,000 chance of impact.Without mentioning NASA findings, Perminov said that he heard from a scientist that Apophis is getting closer and may hit the planet. "I don't remember exactly, but it seems to me it could hit the Earth by 2032," Perminov said."People's lives are at stake. We should pay several hundred million dollars and build a system that would allow to prevent a collision, rather than sit and wait for it to happen and kill hundreds of thousands of people," Perminov said.Scientists have long theorized about asteroid deflection strategies. Some have proposed sending a probe to circle around a dangerous asteroid to gradually change its trajectory. Others suggested sending a spacecraft to collide with the asteroid and alter its momentum, or using nuclear weapons to hit it.Perminov wouldn't disclose any details of the project, saying they still need to be worked out. But he said the mission wouldn't require any nuclear explosions.Hollywood action films "Deep Impact" and "Armageddon," have featured space missions scrambling to avoid catastrophic collisions. In both movies space crews use nuclear bombs in an attempt to prevent collisions."Calculations show that it's possible to create a special purpose spacecraft within the time we have, which would help avoid the collision without destroying it (the asteroid) and without detonating any nuclear charges," Perminov said. "The threat of collision can be averted."Boris Shustov, the director of the Institute of Astronomy under the Russian Academy of Sciences, hailed Perminov's statement as a signal that officials had come to recognize the danger posed by asteroids."Apophis is just a symbolic example, there are many other dangerous objects we know little about," he said, according to RIA Novosti news agency.

The search for extra-terrestrial life assumes two things: that there is some, and that it wants to talk, and while the first is obvious to anyone with even the remotest understanding of the size of the universe the second still poses a lot of questions. The fact is there's only one E.T. whose communications motives we ever understand, and all he wanted was to get off our crazy dirtball. And we made him up.

Those interested in interstellar inquiry (which we really hope is all of you) should check out the METI discussion linked at the end of this post. The Benford brothers launch an interesting discussion on the costs and constraints of any communicating aliens, and while the idea of applying economic limitations to alien life is depressing it's well worth thinking about. There's also a discussion of the motivations for messages, and the sort of signal we should expect from each.

Thinking broadly, high-power transmitters might be built for wide variety of goals other than communication driven by curiosity. Here are a few examples:

Kilroy Was Here. These can be signatures verging on graffiti. Names chiseled into walls have survived from ancient times. More recently, we sent compact disks on interplanetary probes, often bearing people’s names and short messages that can endure for millennia.

High Church. These are designed for durability, to convey the culture’s highest achievements. The essential message is this was the best we did; remember it.

The Funeral Pyre: A civilization near the end of its life announces its existence.

Ozymandias: Here the motivation is sheer pride; the Beacon announces the existence of a high civilization,even though it may be extinct, and the Beacon tended by robots.

Help! Quite possibly societies that plan over time scales ~1000 years will foresee physical problems and wish to discover if others have surmounted them. An example is a civilization whose star is warming (as ours is), which may wish to move their planet outward with gravitational tugs. Many others are possible.

Leakage Radiation: These are unintentional, much like objects left accidentally in ancient sites and uncovered long after. They do carry messages, even if inadvertent: technological fingerprints. These can be not merely radio and television broadcasts radiating isotropically, which are weak, but deep space radar and beaming of energy over solar system distances. This includes “industrial” spaceship launchers, beam-driven sails, “planetary defense” radars scanning for killer asteroids, and cosmic power beaming driving interstellar starships with beams of lasers, millimeter or microwaves.

Believe and Join Us: Religion may be a galactic commonplace; after all, it is here. Seeking converts is common, too, and electromagnetic preaching fits a frequent meme.

Interstellar communication is no easy feat (assuming you haven't found any kind of space-time shortcut). People like to joke about how an aliens first look at us will be I Love Lucy or American Idol (in which case we'll be very lucky to avoid extermination), but physically it'd be easier for the alien to warp here and buy the DVDs. Television transmitters aren't exactly interstellar beacons. The most powerful transmission tower in the world only emits 2.5 Megawatts - assuming zero losses (and while you're at it wish for a unicorn), by the time the signal reaches the closest star it's spread out over 130 billion square kilometers, only twenty picowatts per square meter. Not even a trillionth of a lightbulb and, in case you haven't noticed, the only thing we can see that far away is stars.

We have to assume than any information we intercept is either intentionally beamed at us (or out at random) or based on technology we haven't imagined yet. We should really hope for the latter or it's going to be a long cold existence of extremely slow shouting at each things.

20 December 2009

http://news.slashdot.org/story/09/12/18/0516246/The-Social-Difficulty-of-Saving-Earth-From-an-Asteroid"When it comes to stopping a cataclysmic Earth vs. asteroid event, social science and international political leaders have more difficult questions yet unanswered than physicists do, according to report delivered at this week's American Geophysical Union meeting. Wired has a discussion of an analysis authored by former astronaut Rusty Schweickart, who worries that the international community is nowhere near ready to begin the complex and inevitably controversial task of deflecting an asteroid on a collision course with Earth. Among the questions to be answered is whether to modify the Partial Test Ban Treaty to allow nuclear weapons in outer space. Another possibility to avoid the destruction of civilization would require the international community to choose an area on the globe where an asteroid might be 'aimed.' Who would decide which nations get placed in the asteroid's crosshairs?"

17 December 2009

Astronomers say they have detected a planet just six and a half times as massive as Earth - at a distance so close its atmosphere could be studied, and with a density so low it's almost certain to have abundant water.

The alien world known as GJ 1214b orbits a red dwarf star one-fifth the size of our own sun, 40 light-years away in the constellation Ophiuchus, the astronomers reported in Thursday's issue of the journal Nature.

"Astronomically speaking, this is on our block," David Charbonneau of the Harvard-Smithsonian Center for Astrophysics, lead author of the study, told reporters this week. "This is a next-door neighbor. For perspective, our own TV signals have already passed beyond the distance of this star."

He said the planet was detected using an array of eight off-the-shelf, 16-inch telescopes equipped with commercially available cameras.

"Since we found the super-Earth using a small ground-based telescope, this means that anyone else with a similar telescope and a good CCD camera can detect it too," Charbonneau said in a news release. "Students around the world can now study this super-Earth."

Super-Earths - planets that are roughly two to 10 times Earth's mass - represent the hottest frontier in the years-long search for worlds beyond our solar system. Planet-hunters reported finding their first transiting super-Earth in February, and earlier this week, other researchers addedtwo more super-Earths to the list.

Those planets orbit stars like our own sun, but the brightness of GJ 1214b's parent star is hundreds of times dimmer. The planet is also much closer to the star than any of our own solar system's planets, orbiting at a distance of only 1.3 million miles (2 million kilometers). That combination suggests that the planet's surface temperature would be about 400 degrees Fahrenheit (200 degrees Celsius), Charbonneau's research team reported.

Charbonneau speculated that GJ 1214b was a little too hot for life as we know it, "but it didn't miss it by very much."

The planet's discovery was hailed as a potential breakthrough by Geoffrey Marcy, an astronomer at the University of California at Berkeley who is a pioneer in the planet quest. In a commentary written for Nature, Marcy said Charbonneau and his colleagues "provide the most watertight evidence so far for a planet that is something like our own Earth, outside our solar system."

How it was found
GJ 1214b was detected thanks to an innovative telescope system, a cleverly focused observation campaign - and perhaps a little bit of luck. The eight-telescope array, dubbed the MEarth Project, was set up at the Whipple Observatory on Mount Hopkins in Arizona. The telescopes were programmed to gaze at 2,000 low-mass stars and check for slight, regular dips in light that could be caused by a dark planet's transit across the star's disk.

Relatively dim, relatively close stars were favored because the planet's dimming effect would be more noticeable than it would be with brighter, bigger, farther-out stars.

Just a few months after the MEarth Project began, graduate student Zachory Berta spotted the signature of GJ 1214b's 38-hour orbit. Based on the pattern of the dimming, the team figured out that the planet was 2.7 times as wide as Earth.

The astronomers then turned to another instrument, the HARPS spectrometer on the European Southern Observatory's La Silla telescope in Chile, to figure out the planet's mass. Such mass calculations depend on another technique that checks for the slight wobble in a star's motion caused by a planet's gravitational pull. The HARPS observations indicated that the planet was 6.55 times as massive as Earth.

Putting those measurements together, the team was able to model the planet's density and composition. The best fit for the data was a mixture consisting of about three-quarters water and other ices, one-quarter rock and a gaseous atmosphere.

Implications of a water worldAlthough the surface temperature on GJ 1214b would be well above water's boiling point on Earth's surface, Charbonneau said the planet could nonetheless possess an exotic form of liquid water due to extreme atmospheric pressure at the surface. In today's news release, Berta said the pressure may turn at least some of the water into a rare crystalline form known as ice-seven.

"Despite its hot temperature, this appears to be a water world," Berta said.

On Earth, organisms have been found living near deep-sea hydrothermal vents, where superheated water is held under high pressure. But Charbonneau said he wouldn't want to bet that life could endure under GJ 1214b's crushing conditions.

In fact, it's too early to bet heavily on any detailed description of GJ 1214b. Fortunately, Charbonneau said, the star is close enough that the Hubble Space Telescope could someday analyze the composition of the planet's atmosphere. "That will make it the first super-Earth with a confirmed atmosphere - even though that atmosphere probably won't be hospitable to life as we know it," he said.

Knowing what the atmosphere is made of, and how thick it is, could help astronomers determine whether their characterization of GJ 1214b as a water world is correct. "It's possible that what you have is a ball of rock with a much bigger envelope of light gas," Charbonneau said.

The larger implication of the Nature study is that other super-Earths may be waiting out there with just the right conditions for life. "We found this planet in the first six months," Charbonneau noted. "We had only looked at a small fraction of the stars that we planned to look at through the entire project. That means that either we got really lucky - which is possible - or these planets are common."

Solar Plant in Space Gets Go-Ahead

The 200-megawatt orbiting solar farm would convert solar energy collected in space into radio frequency waves, which would be beamed to a ground station near Fresno, Calif. The radio waves would then be transformed back into electricity and fed into the power grid.

“At the conceptual level, the advantages of space-based systems are significant,” said Michael Peevey, president of the California Public Utilities Commission, during a hearing on Thursday. “This technology would offer around-the-clock access to clean renewable energy, and while there’s no doubt this project has many hurdles to overcome, both regulatory and technological, it’s hard to argue with the audacity of the project.”

A Southern California start-up called Solaren will loft components for the solar power plant into orbit and sell the electricity it generates to Pacific Gas and Electric, the major utility in Northern California, under a 15-year contract. The project is supposed to be turned on in 2016.

Solaren, founded by veterans of Hughes Aircraft, Boeing and Lockheed, plans to deploy a free-floating inflatable Mylar mirror one kilometer (0.62 miles) in diameter. This will collect and concentrate sunlight on a smaller mirror, that in turn will focus the rays on photovoltaic modules, according to the company’s patent.

In an interview with Grist in April, Gary Spirnak, Solaren’s chief executive, said that the vital part of making a space-based solar farm economically viable was to take the weight out of the system to reduce the number of rocket launches.

Still, Mr. Spirnak, who previously ran space shuttle flights for the United States Air Force, acknowledged that putting a solar power plant in space would cost a few billion dollars more than a terrestrial photovoltaic farm generating the equivalent amount of electricity.

The rate that P.G.& E. agreed to pay Solaren for the electricity produced by the solar station remains confidential. Also, regulators said on Thursday that the utility could not count the project toward its renewable energy mandates unless certain milestones were met.

06 December 2009

Space Solar Power discussed on Bharat-Rakshak, the premier website and blog on the Indian Military.http://forums.bharat-rakshak.com/viewtopic.php?f=2&p=783446
The poster asks:QUESTIONS FOR YOU, DEAR BRF MEMBER............1. What do you think is the potential for "Space Based Solar Power" to meet the energy needs of India?2. Have you seen this discussed in the Indian press/media? (If so, please provide links or outline discussions.)3. Who seems 'on board' with this idea? (Politicians, academics, business people -- kindly provide names.)

Here is another Space Solar Power Blog, the Citizen's for Space-Based Solar Power:http://c-sbsp.org/
As of today, it had received 8,005 hits...small, but an increasing number of people have heard of the idea since its renaissance post 2007.

The Space Generation Advisory Council (SGAC) Near Earth Object (NEO) Working Group has released a film about NEOs and planetary defense. The volunteer made documentary presents the opinions of international experts on issues surrounding defending Earth from asteroid and comet impacts.
The general public has constantly feared threatening asteroids. At the same time, scientists and astronomers have long analyzed the potential devastation that an impact from space could cause. Only recently, engineers have been designing realistic missions to stop these natural disasters. Encouraged by this fearful mystery that lies around asteroids, as well as by the latest intense planetary defense research, the SGAC NEO Working Group had the initiative of making a film that conveyed non-exaggerated facts about the dangers we face from space impacts, based on recent research and the opinion of international experts on planetary defense. The film can be watched athttp://www.spacegeneration.org/node/2681[Film is in 4 Parts]

04 December 2009

In a recent seminar coinciding with the International Conference on Space Information Technology (ICST09), held 24-28 Nov, the China Academy of Space Technology (CAST), held a special seminar on Space-Based Solar Power (SBSP) involving researchers from MIT and the Space Journal.

Such projects encourage scientists who dream of harnessing the sun's power directly, without the interruption of cloudy skies and Earth's day-night cycle. Marty Hoffert, a physicist at New York University and one of the staunchest supporters of space solar power, suggests that today's technologies allow space solar power to provide energy as cheaply as the usual solar panel arrays on Earth....Hoffert has pushed for the laser beaming approach as newly effective cost-cutting measure, and even submitted a proposal with his son to ARPA-E, the U.S. Department of Energy's new agency. "The cost to first power doesn't have to be in the hundreds of billions," Hoffert said. His proposal includes laser transmission tests on the ground in an NYU lab, and then a space experiment launched to the International Space Station.